How would you like it if the stock you were long suddenly fell 10% because they announced earnings at 2:30 and you had to cut because you couldn't see the first headline. And then the second headline explained the first and the stock was back to unchanged.

As traders, we like chaos. The companies providing information to their share holders and the public do not. My companies prefer not only to announce after the close, but also have their conference call before the market opens, so every shareholder and potential share holder has the same information and has time to understand it.